A drug-addicted psychopath who murdered four people in a random three-day killing spree had been judged not to pose a risk to the public.

Last night the family of Daniel Gonzalez claimed they had fought for years to make the authorities take his dangerous behaviour seriously.

An Old Bailey jury yesterday took less than 90 minutes to convict Gonzalez of four counts of murder in September 2004 - including the killings of former North Yorkshire couple Derek and Jean Robinson.

After the verdict Gonzalez's mother, Lesley Savage, said she and her family had tried to convince a string of doctors that her son needed treatment for his personality disorder.
The health trust responsible for Gonzalez's treatment said his murderous rampage could not have been "predicted or prevented" but launched an immediate independent inquiry.

Following his arrest, Gonzalez told police he wondered what it would be like to be Nightmare on Elm Street's Freddy Krueger for a day.

Prosecutor Richard Horwell told the jury Gonzalez wanted to be a notorious serial killer of "at least 10 people" in a campaign of murder. He then tried to manipulate psychiatrists into believing that voices commanded him to kill.

Gonzalez, 25, from Woking, Surrey, had denied murdering all four victims - Derek Robinson, 76, and his wife Jean, 68, from Highgate, north London; Kevin Molloy, 46, who was killed in Tottenham, north London, on September 17; and Marie Harding, 73, who was murdered two days earlier near Worthing, Sussex.

He admitted the attempted murder of two people who survived his attacks - Peter King, 61, in Portsmouth, and Koumis Constantino, 59, in Hornsey, north London.

The defence accepted that Gonzalez carried out the killings but claimed he was guilty of manslaughter on the grounds of diminished responsibility because he heard voices commanding him to kill.

Gonzalez sat impassively between five dock officers as the jury delivered its verdicts, as victims' relatives in the public gallery cried and hugged each other.

Judge Ann Goddard remanded Gonzalez into custody until today, when she will fix a minimum term he will serve, possibly in Broadmoor or another secure hospital, after hearing about the impact of the murders on the victims' families.

Speaking outside court, Ms Savage accused police and health officials of failing her son and extended her "sincere condolences" to the victims' families.

Ms Savage said she wanted answers to why, despite "incessant pleas" to health and social services and to the police, her son was turned away and passed from one group of professionals to another without receiving the support he so obviously needed.

"We do not intend to let matters rest here," she said, blaming "human and organisational failings".

"We cannot list here the ever-changing diagnosis that we were offered, the ever-changing advice we were given, the lost and wrongly-recorded notes that misled us and the professionals.

"They, like us and Daniel, were failed by a system that is underfunded and seems incapable of providing joined-up care over any period of time."

But Fiona Edwards, chief executive of Surrey and Borders Partnership NHS Trust, which treated Gonzalez for seven years through its predecessor organisation, said:

"Although he had been treated for mental health problems for a number of years, there is no direct link between his illness and these shocking attacks.

"Mr Gonzalez was a disturbed young man who acted as he did from forces that we may never fully understand."